Analysis of failed mechanical thrombectomy with a focus on technical reasons: Ten years of experience in a single institution

Objective@#Mechanical thrombectomy (MT) is an effective treatment for patients suffering from acute ischemic stroke secondary to large vessel occlusion. However, recanalization failure rates of interventions were about 20% in literature studies. We report our experience of unsuccessful MT with a focus on technical reasons. @*Methods@#From December 2010 to June 2021, six hundred eight patients with acute ischemic stroke due to large artery occlusion received MT using a stent retriever with or without an aspiration catheter in our institution. We divided the reasons for failure into six categories. We analyzed the reasons for failure by dividing our experience time into 3 periods. @*Results@#A total of 608 cases of thrombectomy for large vessel occlusion were identified in the study period. The successful recanalization rate was 90.4%. In most of the cases (20/57, 35%), the thrombus persisted despite several passes, and the second most common cause was termination of the procedure even after partial recanalization (10/57, 18%). Similar proportions of in-stent occlusion, distal embolization, and termination due to vessel rupture were observed. On analysis of three periods, the successful recanalization rate improved over time. @*Conclusions@#MT fails due to various reasons, and intracranial artery stenosis is the main cause of MT failure. With the development of rescue techniques, the failure rate has gradually decreased. Further development of new devices and techniques could improve the recanalization rates.

Analyzing the Significance of T1 Slope minus Cervical Lordosis in Patients with Anterior Cervical Discectomy and Fusion Surgery

Objective@#: Accurate measurement of T1 slope (a component of T1s minus cervical lordosis [CL]) is often constrained by anatomical limitations. In this situation, efforts should be made to find the exact meaning of T1s-CL and whether there are any alternatives to it. @*Methods@#: We enrolled 117 patients who received two-level anterior cervical discectomy and fusion (ACDF). Occipital slope, C2 slope (C2s), C7 slope (C7s), T1, O-C2 angle (O-C2A), C2-7 angle (C2-7A), O-C7 angle (O-C7A), T1s-CL, C7-T1 angle (C7-T1A), and C2-7 sagittal vertical axis were measured. We determined 16° (T1s-CL) as the reference point for dividing subjects into the mismatch group and the balance group, and a comparative analysis was performed. @*Results@#: The mean value of C7-T1A was constantly maintained within 2.6° peri-operatively. In addition, C2s and T1s-CL showed the same absolute change (Δ|0.8|°). The mean values of T1s-CL of the mismatch and balance groups were 23.0° and 7.6°, respectively. The five factors with the largest differences between the two groups were as follows : C2s (Δ13.3°), T1s-CL (Δ15.4°), O-C2A (Δ8.7°), C2-7A (Δ14.7°), and segmental angle (Δ7.9°) before surgery. Only four factors showed statistically significant change between the two groups after ACDF : T1s-CL (Δ4.0° vs. Δ0.2°), C2s (Δ3.2° vs. Δ0.7°), O-C2A (Δ2.6° vs. Δ1.3°), C2-7A (Δ6.3° vs. Δ1.3°). A very strong correlation between T1s-CL and C2s was also found (r=|0.88–0.96|). @*Conclusion@#: C2s itself may be the essential key to represent T1s-CL. The amounts and directions of change of these two factors (T1s-CL and C2s) were also almost identical. The above phenomenon was re-confirmed once again through the correlation analysis.

Modified Orbitozygomatic Approach for Resecting a Parasellar Tumor in a Single Institution

Background@#Modified orbitozygomatic craniotomy is characterized by simplicity and wide exposure. The purpose of the present study was to describe a modified orbitozygomatic approach without resecting the zygomatic arch for large parasellar tumor surgeries. @*Methods@#Between April 2016 and December 2019, seven patients with parasellar tumor underwent surgiest with a modified orbitozygomatic approach. Surgical procedures, clinical outcomes, and complications were analyzed. @*Results@#This study included 3 meningiomas, 2 pituitary adenomas, 1 chondrosarcoma, and 1 schwannoma. Modified orbitozygomatic craniotomy provides a wider surgical freedom in the opticocarotid and prechiasmatic cistern than frontotemporal craniotomy without orbitotomy, Total, subtotal, and partial resections were achieved for 3, 2, and 2 patients, respectively. Reasons for partial resections were tight adhesion to the carotid artery and encasing of the carotid artery. Permanent morbidities developed in one patient with 3rd nerve palsy and one patient with hemiparesis. @*Conclusion@#Modified orbitozygomatic approach can provide the shortest access to the interpeduncular cistern with a minimum brain retraction. Surgeons who experience surgical challenge during the conventional approach for parasellar tumor resection are recommended to learn the modified orbitozygomatic approach.

Preliminary Experience of Neuroform Atlas Stenting as a Rescue Treatment after Failure of Mechanical Thrombectomy Caused by Residual Intracranial Atherosclerotic Stenosis

Objective@#: The low-profile Neuroform Atlas stent can be deployed directly without an exchange maneuver by navigating into the Gateway balloon. This retrospective study assessed the safety and efficacy of Neuroform Atlas stenting as a rescue treatment after failure of mechanical thrombetomy (MT) for large artery occlusion. @*Methods@#: Between June 2018 and December 2019, a total of 31 patients underwent Neuroform Atlas stenting with prior Gateway balloon angioplasty after failure of conventional MT caused by residual intracranial atherosclerotic stenosis (ICAS). Primary outcomes were successful recanalization and patency of the vessel 24 hours after intervention. Secondary outcomes were vessel patency after 14 days and 3-month modified Rankin Scale. Peri-procedural complications, intracerebral hemorrhage (ICH), and 3-month mortality were reviewed. @*Results@#: With a 100% of successful recanalization, median value of stenosis was reduced from 79.0% to 23.5%. Twenty-eight patients (90.3%) showed tolerable vessel patency after 14 days. New infarctions occurred in three patients (9.7%) over a period of 14 days; two patient (6.5%) underwent stent occlusion at 24 hours, and the other patient (3.2%) with delayed stent occlusion had a non-symptomatic dot infarct. There were no peri-procedural complications. Two patients (6.5%) developed an ICH immediately after the procedure with one of them is symptomatic. @*Conclusion@#: Neuroform Atlas stenting seems to be an effective and safe rescue treatment modality for failed MT with residual ICAS, by its high successful recanalization rate with tolerable patency, and low peri-procedural complication rate. Further multicenter and randomized controlled trials are needed to confirm our findings.

Effectiveness and Technical Considerations of Solitaire Platinum 4×40 mm Stent Retriever in Mechanical Thrombectomy with Solumbra Technique

Objective@#: The Solitaire Platinum 4×40 mm stent retriever contains radiopaque markers with a long length. We evaluated the effect of Solitaire Platinum 4×40 mm stent retriever in Solumbra technique thrombectomy, and compared it with shorter Solitaire stent retrievers. @*Methods@#: A total of 70 patients who underwent Solumbra technique thrombectomy with equal diameter (4 mm) and different length (40 vs. 20 mm) Solitaire stent retrievers were divided into two groups : the Solitaire Platinum 4×40 mm stent (4×40) group and the Solitaire FR 4×20 mm stent or Solitaire Platinum 4×20 mm stent (4×20) group. The clinical outcomes, Thrombolysis in Cerebral Infarction score, the first pass reperfusion status, and complications were evaluated and compared between the two groups. Multivariate analysis was performed to evaluate the predictive factors for reperfusion and complete reperfusion from the first pass. @*Results@#: Higher first-pass reperfusion and complete reperfusion were achieved in the 4×40 group (68.0% and 48.0%) than in the 4×20 group (46.7% and 33.3%; p=0.004 and 0.007, respectively). In multivariate analysis, radiopaque device and longer stent retriever were correlated with first-pass reperfusion (p=0.014 and 0.008, respectively) and first-pass complete reperfusion (p=0.022 and 0.012, respectively). @*Conclusion@#: Our study demonstrated the usefulness of the Solitaire Platinum 4×40 mm stent retriever, which led to higher firstpass reperfusion and complete reperfusion rates than the Solitaire FR 4×20 mm stent or the Solitaire Platinum 4×20 mm stent, especially in Solumbra technique thrombectomy.

Effect of Pioglitazone on Perihematomal Edema in Intracerebral Hemorrhage Mouse Model by Regulating NLRP3 Expression and Energy Metabolism

Objective@#: Cerebral edema is the predominant mechanism of secondary inflammation after intracerebral hemorrhage (ICH). Pioglitazone, peroxisome proliferator-activated receptor gamma agonist has been shown to play a role in regulation of central nervous system inflammation. Here, we examined the pharmacological effects of pioglitazone in an ICH mouse model and investigated its regulation on NLRP3 inflammasome and glucose metabolism. @*Methods@#: The ICH model was established in C57 BL/6 mice by the stereotactical inoculation of blood (30 µL) into the right frontal lobe. The treatment group was administered i.p. pioglitazone (20 mg/kg) for 1, 3, and 6 days. The control group was administered i.p. phosphate-buffered saline for 1, 3, and 6 days. We investigated brain water contents, NLRP3 expression, and changes in the metabolites in the ICH model using liquid chromatography-tandem mass spectrometry. @*Results@#: On day 3, brain edema in the mice treated with pioglitazone was decreased more than that in the control group. Expression levels of NLRP3 in the ICH model treated with pioglitazone were decreased more than those of the control mice on days 3 and 7. The pioglitazone group showed higher levels of glycolytic metabolites than those in the ICH mice. Lactate production was increased in the ICH mice treated with pioglitazone. @*Conclusion@#: Our results demonstrated less brain swelling following ICH in mice treated with pioglitazone. Pioglitazone decreased NLRP3-related brain edema and increased anaerobic glycolysis, resulting in the production of lactate in the ICH mice model. NLRP3 might be a therapeutic target for ICH recovery.

The Role of digital subtraction angiography in the ventricular spot sign on the computed tomography angiography

OBJECTIVE: The spot sign on computed tomography angiography is little known about the relationship between the spot sign and the results of cerebral angiography We retrospectively analyzed the spot sign, digital subtraction angiography results, and other factors.MATERIAL AND METHODS: From December 2009 to May 2014, DSA was performed in 52 ICH patients with non-specific location or abnormalities on CTA findings. 26 of those patients, whose initial CTA showed the spot sign, were analyzed. Two groups, one with the spot sign in the ventricle (Group A) and others with the spot sign in another location (Group B) were statistically compared.RESULTS: The mean age of the study subjects was 46.9 years (range, 15 to 80 years) and the percentage of males was 53.8%. Thirteen of 26 patients had ICH without intraventricular hemorrhage, and 6 patients had co-existing IVH. In 17 cases, the DSA results were negative. Seven patients were diagnosed with pseudoaneurysms, and two cases showed developmental venous anomalies. Group A consisted of the 8 patients (30.8%) who showed the spot sign in a ventricle. The number of pseudoaneurysms was statistically significantly higher in Group A than in Group B (71.4% versus 28.6%; OR, 13.3; 95% CI, 1.7-103.8 P = 0.014). All three patients who underwent endovascular treatment were members of Group A (P = 0.022), whereas most (92.3%) of those in Group B underwent surgical evacuation. (P = 0.030).CONCLUSION: When CTA shows the spot sign in a ventricle, it is a clue that an existing underlying vascular lesion requires endovascular treatment.

Endovascular Treatments Performed Collaboratively by the Society of Korean Endovascular Neurosurgeons Members: A Nationwide Multicenter Survey

OBJECTIVE: Since less invasive endovascular treatment was introduced to South Korea in 1994, a considerable proportion of endovascular treatments have been performed by neuroradiology doctors, and endovascular treatments by vascular neurosurgeons have recently increased. However, few specific statistics are known regarding how many endovascular treatments are performed by neurosurgeons. Thus, authors compared endovascular treatments collaboratively performed by vascular neurosurgeons with all cases throughout South Korea from 2013 to 2017 to elucidate the role of neurosurgeons in the field of endovascular treatment in South Korea.METHODS: The Society of Korean Endovascular Neurosurgeons (SKEN) has issued annual reports every year since 2014. These reports cover statistics on endovascular treatments collaboratively or individually performed by SKEN members from 2013 to 2017. The data was requested and collected from vascular neurosurgeons in various hospitals. The study involved 77 hospitals in its first year, and 100 in its last. National statistics on endovascular treatment from all over South Korea were obtained from the Healthcare Bigdata Hub website of the Health Insurance Review & Assessment Service based on the Electronic Data Interchange (EDI) codes (in the case of intra-arterial (IA) thrombolysis, however, statistics were based on a combination of the EDI and I63 codes, a cerebral infarction disease code) from 2013 to 2017. These two data sets were directly compared and the ratios were obtained.RESULTS: Regionally, during the entire study period, endovascular treatments by SKEN members were most common in Gyeonggi-do, followed by Seoul and Busan. Among the endovascular treatments, conventional cerebral angiography was the most common, followed by cerebral aneurysmal coiling, endovascular treatments for ischemic stroke, and finally endovascular treatments for vascular malformation and tumor embolization. The number of endovascular treatments performed by SKEN members increased every year.CONCLUSION: The SKEN members have been responsible for the major role of endovascular treatments in South Korea for the recent 5 years. This was achieved through the perseverance of senior members who started out in the midst of hardship, the establishment of standards for the training/certification of endovascular neurosurgery, and the enthusiasm of current SKEN members who followed. To provide better treatment to patients, we will have to make further progress in SKEN.

Change of Extracellular Glutamate Level in Striatum during Deep Brain Stimulation of the Entopeduncular Nucleus in Rats

OBJECTIVE: Globus pallidus interna (GPi) is acknowledged as an essential treatment for advanced Parkinson’s disease (PD). Nonetheless, the neurotransmitter study about its results is undiscovered. The goal of this research was to examine influences of entopeduncular nucleus (EPN) stimulation, identical to human GPi, in no-lesioned (NL) rat and 6-hydroxydopamine (6-HD)-lesioned rat on glutamate change in the striatum.METHODS: Extracellular glutamate level changes in striatum of NL category, NL with deep brain stimulation (DBS) category, 6-HD category, and 6-HD with DBS category were examined using microdialysis and high-pressure liquid chromatography. Tyrosine hydroxylase (TH) immunoreactivities in substantia nigra and striatum of the four categories were also analyzed.RESULTS: Extracellular glutamate levels in the striatum of NL with DBS category and 6-HD with DBS category were significantly increased by EPN stimulation compared to those in the NL category and 6-HD category. EPN stimulation had no significant effect on the expression of TH in NL or 6-HD category.CONCLUSION: Clinical results of GPi DBS are not only limited to direct inhibitory outflow to thalamus. They also include extensive alteration within basal ganglia.

Endovascular Treatments Performed Collaboratively by the Society of Korean Endovascular Neurosurgeons Members: A Nationwide Multicenter Survey

OBJECTIVE: Since less invasive endovascular treatment was introduced to South Korea in 1994, a considerable proportion of endovascular treatments have been performed by neuroradiology doctors, and endovascular treatments by vascular neurosurgeons have recently increased. However, few specific statistics are known regarding how many endovascular treatments are performed by neurosurgeons. Thus, authors compared endovascular treatments collaboratively performed by vascular neurosurgeons with all cases throughout South Korea from 2013 to 2017 to elucidate the role of neurosurgeons in the field of endovascular treatment in South Korea. METHODS: The Society of Korean Endovascular Neurosurgeons (SKEN) has issued annual reports every year since 2014. These reports cover statistics on endovascular treatments collaboratively or individually performed by SKEN members from 2013 to 2017. The data was requested and collected from vascular neurosurgeons in various hospitals. The study involved 77 hospitals in its first year, and 100 in its last. National statistics on endovascular treatment from all over South Korea were obtained from the Healthcare Bigdata Hub website of the Health Insurance Review & Assessment Service based on the Electronic Data Interchange (EDI) codes (in the case of intra-arterial (IA) thrombolysis, however, statistics were based on a combination of the EDI and I63 codes, a cerebral infarction disease code) from 2013 to 2017. These two data sets were directly compared and the ratios were obtained. RESULTS: Regionally, during the entire study period, endovascular treatments by SKEN members were most common in Gyeonggi-do, followed by Seoul and Busan. Among the endovascular treatments, conventional cerebral angiography was the most common, followed by cerebral aneurysmal coiling, endovascular treatments for ischemic stroke, and finally endovascular treatments for vascular malformation and tumor embolization. The number of endovascular treatments performed by SKEN members increased every year. CONCLUSION: The SKEN members have been responsible for the major role of endovascular treatments in South Korea for the recent 5 years. This was achieved through the perseverance of senior members who started out in the midst of hardship, the establishment of standards for the training/certification of endovascular neurosurgery, and the enthusiasm of current SKEN members who followed. To provide better treatment to patients, we will have to make further progress in SKEN.

Change of Extracellular Glutamate Level in Striatum during Deep Brain Stimulation of the Entopeduncular Nucleus in Rats

OBJECTIVE: Globus pallidus interna (GPi) is acknowledged as an essential treatment for advanced Parkinson’s disease (PD). Nonetheless, the neurotransmitter study about its results is undiscovered. The goal of this research was to examine influences of entopeduncular nucleus (EPN) stimulation, identical to human GPi, in no-lesioned (NL) rat and 6-hydroxydopamine (6-HD)-lesioned rat on glutamate change in the striatum. METHODS: Extracellular glutamate level changes in striatum of NL category, NL with deep brain stimulation (DBS) category, 6-HD category, and 6-HD with DBS category were examined using microdialysis and high-pressure liquid chromatography. Tyrosine hydroxylase (TH) immunoreactivities in substantia nigra and striatum of the four categories were also analyzed. RESULTS: Extracellular glutamate levels in the striatum of NL with DBS category and 6-HD with DBS category were significantly increased by EPN stimulation compared to those in the NL category and 6-HD category. EPN stimulation had no significant effect on the expression of TH in NL or 6-HD category. CONCLUSION: Clinical results of GPi DBS are not only limited to direct inhibitory outflow to thalamus. They also include extensive alteration within basal ganglia.

Risk factors of bilateral chronic subdural hematoma compared to unilateral chronic subdural hematoma

Chronic subdural hematoma (CSDH) is a common and relatively benign disease. The aim of this study was to investigate the differences between unilateral and bilateral chronic subdural hematoma in terms of predisposing factors. A retrospective analysis was made of all patients who underwent operation for CSDH at our institution between January 2010 and December 2015. Patients were divided into two groups (unilateral versus bilateral CSDH) and univariate and multivariate analysis was performed to assess demographic data, symptoms, cause of SDH, medical history, laboratory data, and initial radiologic findings. A total of 246 patients were enrolled. There were 63 (25.6%) patients with bilateral CSDH. There were no significant differences concerning sex and initial symptoms between the two groups. Only malignancy history was a significant risk factor for bilateral CSDH in both univariate and multivariate analysis (p = 0.002 and 0.001, respectively). In multivariate analysis, diabetes mellitus (OR 2.03, 95% CI: 1.05 - 3.92, p = 0.0350), malignancy (OR 5.09, 95% CI: 1.93 - 13.40, p= 0.0010), membrane septation (OR 0.50, 95% CI: 0.25 - 0.96, p = 0.0392), and brain atrophy (mild: OR 2.34, 95% CI: 1.16 - 4.71, p = 0.0164, moderate: OR 3.85, 95% CI: 1.32-11.18, p = 0.0131) were significantly associated with bilateral CSDH. The present study suggests that diabetes mellitus, malignancy, membrane septation and mild to moderate brain atrophy is independent predisposing factors of bilateral CSDH.

Coil Embolization of Ruptured Proximal Posterior Inferior Cerebellar Artery Aneurysm with Contralateral Retrograde Approach for LVIS Jr. Intraluminal Support Deployment

The safety and feasibility of simple coil embolization and stent deployment for the treatment of posterior inferior cerebellar artery (PICA) aneurysms, as well as their radiologic and clinical results, have not been adequately understood. Especially, if dissecting aneurysm of proximal PICA is associated with small caliber PICA and stenosis of ipsilateral vertebral artery orifice (VAO), endovascular coiling with saving of PICA is not always easy. This 64-year-old man presented with subarachnoid hemorrhage due to a ruptured dissecting aneurysm of left proximal PICA. The aneurysm was irregularly fusiform in nature with a shallow PICA orifice (1.4 mm) and narrow caliber (0.9–1.5 mm). Moreover, the ipsilateral VAO showed severe stenosis (1.8 mm). We performed bifemoral puncture and chose additional route from right vertebral artery to left vertebrobasilar junction for retrograde approach and deployment of LVIS Jr. intraluminal support at proximal PICA. And then, the antegrade approach and coiling of aneurysm was done. Despite of transient thrombus of PICA, the aneurysm was successfully secured with preservation of whole PICA course. For preservation of narrow PICA with ipsilateral VAO stenosis, the contralateral approach and deployment of LVIS Jr. intraluminal support may be considered.

Effectiveness and Safety of Mechanical Thrombectomy with Stent Retrievers in Basilar Artery Occlusion: Comparison with Anterior Circulation Occlusions

OBJECTIVE: Acute basilar artery occlusion (BAO) is associated with severe neurological dysfunction and high mortality rates. The benefits of mechanical thrombectomy in BAO have not been explored in recent clinical trials. Therefore, we analyzed outcomes of stent retriever mechanical thrombectomy for BAO, and compared with anterior circulation occlusions (ACO). METHODS: In total, 161 consecutive patients (24 BAO, 137 ACO) who underwent mechanical thrombectomy with the stent retriever between January 2013 and August 2016 enrolled in our study. All patients underwent clinical assessment with the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS). Radiological results were used to evaluate thrombolysis in cerebral infarction (TICI) scores and successful recanalization was defined by TICI 2b or 3. RESULTS: Mean NIHSS scores at 24 hours and 30 days were significantly higher in the BAO group than the ACO group (p=0.021, p=0.001). mRS at 90 days was significantly higher in the BAO group (4.2) compared with the ACO group (3.0) (p=0.003). The BAO group (2.0) performed fewer stent retriever passages than the ACO group (2.7) (p=0.049). There were no significant differences between the two groups in terms of complications, but the BAO patients experienced a higher mortality (16.6%) rate than ACO patients (5.8%) (p=0.001). In subgroup analysis of BAO, patients with short procedure times achieved successful recanalization (p=0.001) and successfully recanalized patients exhibited more favorable mRS at 90 days (p=0.027). CONCLUSION: In our study, mechanical thrombectomy of BAO patients showed worse clinical outcome and higher mortality rate than ACO patients. However, mechanical thrombectomy with a stent retriever in BAO is an effective treatment, because successfully recanalized patients showed good clinical outcome in BAO patients.

Significances and Outcomes of Mechanical Thrombectomy for Acute Infarction in Very Elderly Patients: A Single Center Experience

OBJECTIVE: Mechanical thrombectomy is increasingly being used for the treatment of acute ischemic stroke. The population over 80 years of age is growing, and many of these patients have acute infarction; however, these patients are often excluded from clinical trials, so the aim of this study was to compare the functional outcomes and complication rates in very elderly patients (age ≥80 years) and aged patients (60–79 years) treated with mechanical thrombectomy. METHODS: Between January 2010 and June 2015, we retrospectively reviewed 113 senior patients (over 60 years old) treated at our institution for acute ischemic stroke with mechanical thrombectomy. They were divided into a very elderly (≥80 years) and aged (60–79 years) group, with comparisons in recanalization rates, complications, death and disability on discharge be reported. RESULTS: The mean age was 70.3 years in the aged group and 83.4 years in the very elderly group. Elderly patients had higher rates of mechanical thrombectomy failure than the younger group (40% vs. 14%; odds ratio [OR] 4.1; 95% confidence interval [CI] 1.4–11.9; p=0.012). Results from thrombolysis in cerebral ischemia and modified Rankin scale at discharge were worse in the older group (p=0.005 and 0.023 respectively). There were no differences in mortality rate or other complications, but infarction progression rates were significantly higher in the very elderly group. (15% vs. 2.2%; OR 8.0; 95% CI 1.2–51.7; p=0.038). The majority (92.3%) of the patients who failed in aged group were not successful after several trials. However, in half (4 of 8) of the very elderly group, the occlusion site could not be accessed. CONCLUSION: Patients older than 80 years of age undergoing mechanical thrombectomy for acute infarction were more difficult to recanalize due to inaccessible occlusion sites and had a higher rate of infarction progression, However, mortality and other complications were similar to those in younger patients.

Predictive Factors for Recurrence after Burr-Hole Craniostomy of Chronic Subdural Hematoma

OBJECTIVE: Chronic subdural hematoma is a common and relatively benign disease. However, recurrence is common after surgical treatment, and the recurrence rate varies from 5% to 33%. The aim of this study was to investigate the predictive factors for recurrence of chronic subdural hematoma. METHODS: We analyzed data from 248 patients with chronic subdural hematoma who were treated by burr-hole craniostomy with a closed drainage system for hematoma evacuation in this five-year retrospective study. RESULTS: Thirty-one (12.6%) patients underwent re-operation for recurrence of chronic subdural hematoma. Univariate analysis revealed that anticoagulation (p=0.0279), headache (p=0.0323), and preoperative midline shifting (p=0.0321) showed significant differences with respect to recurrent chronic subdural hematoma. We performed a multivariate logistic regression analysis and found that diabetes mellitus (odds ratio [OR], 2.618; 95% confidence interval [CI], 1.0899–6.2898; p=0.0314), anticoagulation (OR, 6.739; 95% CI, 1.1287–40.2369; p=0.0364), headache (OR, 2.951; 95% CI, 1.1464–7.5964; p=0.0249), and preoperative midline shifting (OR, 1.0838; 95% CI, 1.0040–1.1699; p=0.0391) were independent predictive factors for recurrence of chronic subdural hematoma. CONCLUSION: We showed that diabetes mellitus, anticoagulation, headache, and preoperative midline shifting were independent predictors of recurrence of chronic subdural hematoma.

Horizontal Stent Assisted Coiling of Wide Neck Basilar Tip Aneurysm: Comparison of Two Cases

Currently, endovascular coiling is a popular treatment for basilar tip aneurysms, which usually involve a wide neck. Serious complications can occur when the posterior cerebral artery (PCA) originating from a wide neck is not properly preserved. Accordingly, various adjunctive procedures using stents or a balloon have been introduced. Herein we report two cases of basilar tip aneurysms in which retrograde horizontal (from one PCA to the other PCA) stent-assisted coiling was successful, and we provide a summary of the important technical points.

Striatal Glutamate and GABA after High Frequency Subthalamic Stimulation in Parkinsonian Rat

OBJECTIVE: High frequency stimulation (HFS) of the subthalamic nucleus (STN) is recognized as an effective treatment of advanced Parkinson’s disease. However, the neurochemical basis of its effects remains unknown. The aim of this study is to investigate the effects of STN HFS in intact and 6-hydroxydopamine (6-OHDA)-lesioned hemiparkinsonian rat model on changes of principal neurotransmitters, glutamate, and gamma-aminobutyric acid (GABA) in the striatum. METHODS: The authors examined extracellular glutamate and GABA change in the striatum on sham group, 6-OHDA group, and 6-OHDA plus deep brain stimulation (DBS) group using microdialysis methods. RESULTS: High-pressure liquid chromatography was used to quantify glutamate and GABA. The results show that HFS-STN induces a significant increase of extracellular glutamate and GABA in the striatum of 6-OHDA plus DBS group compared with sham and 6-OHDA group. CONCLUSION: Therefore, the clinical results of STN-HFS are not restricted to the direct STN targets but involve widespread adaptive changes within the basal ganglia.

Clinical and Radiological Comparison between Ipsilateral and Contralateral Side Canal Decompression Using an Unilateral Laminotomy Approach

OBJECTIVE: To compare the clinical and radiological outcome of both sides using the unilateral approach. METHODS: Unilateral laminotomy was performed to achieve bilateral decompression. Thirty-nine patients who underwent this procedure were analyzed prospectively using the Oswestry Disability Index (ODI), the visual analog scale (VAS) pain score to evaluate symptoms in both legs, and the radiological morphometric index to calculate the anteriorposterior diameter and midcanal width. The incidence of complications from this approach was then evaluated. RESULTS: The mean follow-up time was 12.2 months. The mean ODI was 48.4 preoperatively and 14.2 postoperatively. The mean dural sac widening of the ipsilateral side (187.0%) was significantly larger (p<0.01) than that of the the contralateral side (145.6%). The VAS improvement ratio ([preoperative VAS score-postoperative VAS score]/[preoperative VAS score]×100) for the pain in each leg was 75.4%(ipsilateral side) and 73.7%(contralateral side). While the VAS improvement ratio for pain in each side was significantly reduced, the difference in the VAS ratio between sides was statistically insignificant (p=0.64). There were 2 cases (5.1%) of dural tearing during the procedure, 1 case (2.6%) of transient paresthesia of nerve roots, and 2 cases (5.1%) of transient paresthesia of the contralateral nerve root. The transient paresthesias of nerve roots never lasted more than 2 weeks. CONCLUSION: This technique allows for significant decompression of the contralateral canal and excellent clinical outcomes without troublesome complications. Although ipsilateral the dural sac widening was significantly larger than contralateral side, the difference in the clinical outcome between sides was statistically insignificant.

Evaluation and Treatment of the Acute Cerebral Infarction with Convexal Subarachnoid Hemorrhage

Non-traumatic convexal subarachnoid hemorrhage (CSAH) is a comparatively infrequent with various vascular and nonvascular causes, it rarely occurs concomitant to acute ischemic stroke. We report a case of a 59-year-old woman, visited emergency room with right side subjective weakness spontaneously. Magnetic resonance diffusion-weighted images revealed an acute infarction of anterior cerebral arterial territory. Computed tomographic angiography showed a left frontal CSAH without any vascular lesions. And other laboratory studies were non-specific. We treated with dual antiplatelet drugs (cilostazole [Otsuka Pharmaceutical Co., Ltd. tokyo, Japan] and Aspirin [Bayer Pharma AG., Leverkusen, Germany]). She has done well for a follow-up period. (5 months) This case demonstrates the CSAH with acute infarction is rare but need to work up to identify the etiology and antiplatelet dugs are taken into account for treatments.